It is known in the art that the strength of a beverage can end may be increased if a scored pour opening is oriented properly with respect to the direction of the metal texture, i.e., grain structure. Prior to this invention, efforts to orient disk-shaped parts have focused primarily on intentionally providing non-functional physical deformations to identify the orientation of the metal grain texture of a can end or to locate an area of the can end for subsequent manufacturing processes.
U.S. Pat. No. 4,016,968 to Stelter rotates a can end with a reciprocating mandrel until a preformed tab in the can end engages a sensor lug. When the sensor lug is engaged, a clutch slips and the oriented part is then transported from the orientation mandrel.
U.S. Pat. No. 3,628,650 to Rouse discloses another means of mechanically orienting a can end using a plurality of rotating wheels. Can ends having preformed embossments are individually rotated until the embossments align with similarly shaped rollers located underneath the can end and gravitational force causes the can end to seat on the similarly shaped rollers, thereby pulling the can end away from the other plurality of driving rotating wheels. The can end may then be removed from the apparatus in an oriented position.
U.S. Pat. Nos. 2,968,387 and 3,297,134 to Lagler and Pastuszak respectively rotate disk-shaped objects and utilize preformed physical shapes of the disks to achieve a common orientation.
U.S. Pat. Nos. 4,776,447 and 4,721,199 to Pitcher and Ioannides respectively disclose devices for orienting can ends using outwardly extending members which are inserted into preformed cut-outs in the can ends. The outwardly extending members are moved in a predetermined path so that the can ends are thereby oriented.
All of these prior methods have the disadvantage of using some preformed physical shape or deformation in each of the disk-shaped objects to mechanically determine the angular orientation.
It is also known in the art to use scanning equipment to inspect cans or can ends for quality imperfections of various kinds. For example, U.S. Pat. No. 4,497,409 to Chong describes a seam inspection apparatus in which an electronic scanner is used to inspect the seams of a can to determine whether certain quality standards are complied with.